We are happy to announce the release of Spire.XLS 11.9.3. This version supports converting Excel to UOS/OFD. More details are listed below. Here is a list of changes made in this release Category ID Description New feature - Supports converting Excel to UOS. Workbook workbook = new Workbook(); workbook.LoadFromFile(xlsxFile); workbook.SaveToFile(uosFile, FileFormat.UOS); New feature - Supports converting Excel to OFD Workbook workbook = new Workbook(); workbook.LoadFromFile(xlsxFile); workbook.SaveToFile(ofdFile, FileFormat.OFD); Click the link to download Spire.XLS 11.9.3: https://www.e-iceblue.com/Download/download-excel-for-net-now.html More information of Spire.XLS new release or hotfix: https://www.e-iceblue.com/forum/spire-xls-new-release-or-hotfix-t4630.html